The annual scramble for Comic-Con hotel rooms will begin Tuesday morning when those lucky enough to have already nabbed a badge will try to secure lodging as well.

The online reservations process will begin at 9 a.m. Pacific time. The link to the online site overseen by the agency, Travel Planners, already has been sent to those who will be attending the four-day convention, to be held July 18-21.

More than 50 hotels, many of them located in downtown San Diego and Mission Valley, are part of the room block set aside for the convention. Because they are offering special, discounted rates, they tend to sell out within the first hour.

Rates charged by hotel rooms not in the convention block, tend to be much higher during Comic-Con when demand for lodging is especially high throughout the county. More than 130,000 attendees are expected, although a large number of those are local.

The first-come, first-served system for securing a room requires those making a reservation to provide their top six hotel choices in order of preference.

Badges for the always sold-out convention went on sale more than a week ago, and four-day and single-day tickets sold out in less than two hours. Comic-Con International has held out the possibility of a second sale if there are enough returned badges or cancellations.